1. Field of the Invention
This invention relates to a radio communication system comprising a slave unit and a master unit, the slave unit and a communication method. In particular, this invention relates to a radio communication system, a slave unit, a master unit and a communication method in which the slave unit detects predetermined data and the master unit collects the data detected by the slave unit.
2. Description of Background Art
Conventional radio communication systems including a slave unit and master unit are disclosed, for example, in Japanese unexamined patent publication Nos. 2004-341648 and 2003-30773. The radio communication system in patent publication No. 2004-341648 includes a slave unit provided with an operating section for a communication test that transmits a test radio wave to a master unit. The transmission of the test radio wave is operated by the operating section to be delayed so that the test radio wave is transmitted after a door of a pipe shaft or the like is closed.
On the other hand, patent publication No. 2003-30773 discloses that a radio slave unit operates an external signal detection section therein and transmits data after a lapse of a delay time, and the delay time can be set to a desired value.
The conventional radio communication systems including the slave unit and master unit have the above-described structure and are capable of delaying the transmission of the test radio wave from the slave unit and setting the delay time; however, there is no specific description of the setting method of the delay time, and therefore the way of setting the delay time is unknown.